NERC Tag versions
NERC Tag 1.x
The earliest NERC Tag application was based on a Microsoft Excel spreadsheet, and was introduced in 1997. The form was usually completed by the power marketers or schedulers, by defining the date and time of the transaction, the physical path of the energy schedule from its point of generation to point of consumption, the financial path (buying/selling chain) of the energy schedule, the hourly energy amounts scheduled to flow, and also the OASIS transmission requests for each power system crossed which thereby documented that permission to cross each power system had been properly obtained.
Elements of a NERC Tag included Control Areas (CA), Transmission Providers (TP), Purchasing/Selling Entities (PSE), transmission Points of Receipt (POR) and Points of Delivery (POD), as well as product codes for several transmission and generation priorities.
The physical path was the most important aspect of the NERC Tag in terms of understanding the impact of a collection of individual transactions after they had been compiled into a single complete transaction. To complete the physical path it was necessary to identify the power system and power plant where the energy was to be generated, any and all power systems that would be utilized to move the energy to its eventual destination, and lastly the power system and location of the delivery point where the energy would be consumed (the "load").
When a NERC Tag was created in the spreadsheet, the information was then distilled into a small CSV formatted data packet which was disseminated via e-mail to all of the participants listed on the NERC tag. In this way, all participants of a transaction were able to determine which other electric utilities and power marketers were involved in the transaction, and what the roles of the other participants were. More importantly, in the event of a contingency such as a transmission line outage or generation failure, all participants could more easily be notified of the schedule change, and could then all act in cooperation to curtail the scheduled transaction.
The NERC Tag 1.0 implementation was not capable of collecting schedule flow data in any useful way, but it did serve to familiarize schedulers with the demands of tagging their transactions, a process that would eventually be mandatory. A database of transmission scheduling points maintained by NERC through the Transmission System Information Networks (TSIN) that was originally developed for the OASIS nodes was greatly expanded to include additional information required in the process of creating NERC Tags.
The spreadsheet-based NERC Tag application saw minor improvements in functionality and scope with small incremental changes which advanced it to NERC Tag 1.3, although there was not much discernible difference to the participants, and until version 1.4 was implemented, any previous version could still be used.
E-Tag 1.4 and 1.5
Not long after NERC introduced the NERC Tag spreadsheet and packet emailer, NERC concluded that it did not want involvement in any future software development or maintenance. A NERC Tag specification document, version 1.4, was drafted as the next level in energy tagging, the NERC Tag would subsequently also be known as an E-Tag. Data transfer would now occur directly over an Internet connection instead of via e-mail. This eliminated the cumbersome process required to receive a data packet via email and port it back into the original spreadsheet-based tagging application. This change made the NERC Tag much easier to use in a real-time application. E-Tag 1.4 went into effect in 1999, but was replaced just nine months later with E-Tag 1.5, followed three months later with E-Tag 1.501. The 1.5 and 1.501 Specs corrected the shortcomings experienced with the initial release of the first E-Tag Spec.
Although NERC was responsible for the E-Tag Spec, it opened development of the application to run it to the software market. Initially there were numerous E-Tagging software providers, mainly a mix of small start-ups and new applications developed by existing energy industry software developers. The E-Tag 1.5 Spec was written in such a way that the various applications were permitted to have differing graphical user interfaces (GUIs), but functionally "under the hood" they were required to be able to interact with each other when transmitting, receiving and processing E-Tags. A new feature introduced with E-Tag 1.4/1.5, made possible by the real-time sharing of E-Tags, was the ability for reliability entities (namely the CA's and TP's) in the E-Tag to electronically approve or deny E-Tags based on various criteria.
The arrival of real-time tagging also enabled NERC to begin collecting real-time and short-term future data regarding the energy transactions scheduled throughout the North American power grid. The data from approved transactions was ported to the Interchange Distribution Calculator (IDC), where the data could be applied to a virtual study model of the Eastern Interconnection. The IDC went online in 1999.
E-Tag 1.6
Building on the lessons experienced with E-Tag applications to date, E-Tag 1.6 went into effect in 2000. There were seven variations of E-Tag 1.6, up to E-Tag 1.67 which was in effect until late 2002. Most of the changes in E-Tag 1.6 were of a functional nature and not overly apparent to the users.
Under E-Tag 1.6, NERC implemented the "no tag, no flow" rule, where all energy transactions were to be documented with an E-Tag. Accurate system studies of the Eastern Interconnection in order to determine which schedules should be curtailed would only be possible if every transaction was tagged and therefore included in the IDC calculations. Reliability Coordinators in the Eastern Interconnection could access the IDC online and run flow studies based on various operating scenarios with all of the current energy schedules derived from the E-Tags. When an actual contingency occurred, the Reliability Coordinators could identify the constrained transmission line or corridor within the IDC, and the IDC would then identify which E-Tagged schedules should be curtailed in order to ease the loading on the restricted facilities.
E-Tag 1.7
NERC's E-Tag 1.7 Specification completely reworked the E-Tag platform from scratch. Some users said that it was so significant that it might have been more appropriate to have called it "E-Tag 2.0". For the first time, Extensible Markup Language (XML) was utilized to format the data transferred between E-Tag applications, finally replacing the base CSV data transfer format based on its ancestral NERC Tag 1.0 spreadsheet/e-mail origins. The TSIN database was expanded to include generation and load points which were matched with PSEs that had rights to schedule them, and also included complex associations that enforced matched sets of PORs and PODs with TPs. E-Tag 1.7 also greatly expanded the time frame flexibility of an E-Tag by allowing extensions and modifications with comprehensive approval processes, layering of multiple OASIS requests for transmission rights, and also fully automated the tag curtailment functions from the IDC so that individual manual tag curtailments were no longer necessary.
Shortly after E-Tag 1.7 went online in 2002, the Western Electricity Coordinating Council (WECC) implemented the WECC Unscheduled Flow (USF) Tool, which accomplished a similar automated curtailing capability for the Western Interconnection that the IDC had done for the Eastern Interconnection.
The number of software choices for E-Tag software dwindled within the first few years to a handful of major players. The number of E-Tag users was strictly limited by the number of entities involved in E-Tagging, and the cost of complying with NERC E-Tag Specifications became prohibitive for any software company that did not already have significant market share or adequate financial backing. The added complexities of E-Tag 1.7 dealt a severe blow to most of the E-Tagging software providers, and within a year of E-Tag 1.7 going online, there was only one dominant E-Tag software provider remaining, which also provided all IDC and WECC USF services, though a few holdouts and customer-developed "in-house" E-Tag applications remain.
Version 1.7.097 of E-Tag was implemented on January 3, 2007.
E-Tag 1.8
Five years following the release of E-Tag 1.7, a major update was developed and implemented on December 4, 2007. E-Tag 1.8 cleaned up some long-standing issues not easily addressed with minor revisions to E-Tag 1.7 and brought the E-Tag applications back up to current industry policy standards.
The Federal Energy Regulatory Commission (FERC) is the United States federal agency that regulates the transmission and wholesale sale of electricity and natural gas in interstate commerce and regulates the transportation of oil by pipeline in interstate commerce. FERC also reviews proposals to build interstate natural gas pipelines, natural gas storage projects, and liquefied natural gas (LNG) terminals, in addition to licensing non-federal hydropower projects.
The North American Electric Reliability Corporation (NERC) is a nonprofit corporation based in Atlanta, Georgia, and formed on March 28, 2006, as the successor to the North American Electric Reliability Council. The original NERC was formed on June 1, 1968, by the electric utility industry to promote the reliability and adequacy of bulk power transmission in the electric utility systems of North America. NERC's mission states that it is to "ensure the reliability of the North American bulk power system."
The electric power industry covers the generation, transmission, distribution and sale of electric power to the general public and industry. The commodity sold is actually energy, not power, e.g. consumers pay for kilowatt-hours, power multiplied by time, which is energy. The commercial distribution of electricity started in 1882 when electricity was produced for electric lighting. In the 1880s and 1890s, growing economic and safety concerns lead to the regulation of the industry. What was once an expensive novelty limited to the most densely populated areas, reliable and economical electric power has become an essential aspect for normal operation of all elements of developed economies.
The Open Access Same-Time Information System (OASIS), is an Internet-based system for obtaining services related to electric power transmission in North America. It is the primary means by which high-voltage transmission lines are reserved for moving wholesale quantities of electricity. The OASIS concept was originally conceived with the Energy Policy Act of 1992, and formalized in 1996 through Federal Energy Regulatory Commission (FERC) Orders 888 and 889.
A regional transmission organization (RTO) in the United States is an electric power transmission system operator (TSO) that coordinates, controls, and monitors a multi-state electric grid. The transfer of electricity between states is considered interstate commerce, and electric grids spanning multiple states are therefore regulated by the Federal Energy Regulatory Commission (FERC). The voluntary creation of RTOs was initiated by FERC Order No. 2000, issued on December 20, 1999. The purpose of the RTO is to promote economic efficiency, reliability, and non-discriminatory practices while reducing government oversight.
The Texas Interconnection is an alternating current (AC) power grid – a wide area synchronous grid – that covers most of the state of Texas. The grid is managed by the Electric Reliability Council of Texas (ERCOT).
The Eastern Interconnection is one of the two major alternating-current (AC) electrical grids in the North American power transmission grid. The other major interconnection is the Western Interconnection. The three minor interconnections are the Quebec, Alaska, and Texas interconnections.
The Western Interconnection is a wide area synchronous grid and one of the two major alternating current (AC) power grids in the North American power transmission grid. The other major wide area synchronous grid is the Eastern Interconnection. The minor interconnections are the Québec Interconnection, the Texas Interconnection, and the Alaska Interconnections.
ReliabilityFirst (RF) is one of the six Federal Energy Regulatory Commission (Commission)-approved regional entities responsible for ensuring the reliability of the North American Bulk-Power System, pursuant to the Energy Policy Act of 2005. ReliabilityFirst performs this function pursuant to and under its delegation agreement with North American Electric Reliability Corporation (NERC), which is the Commission-approved Electric Reliability Organization. NERC and the Regional Entities are non-governmental, self-regulatory organizations that were created in recognition of, among other things, the complex, interconnected, and international nature of the North American Bulk Power-System.
The Western Electricity Coordinating Council (WECC) promotes Bulk Electric System (BES) reliability for the entire Western Interconnection system. WECC is the Regional Entity responsible for compliance monitoring and enforcement. In addition, WECC provides an environment for the development of Reliability Standards and the coordination of the operating and planning activities of its members as set forth in the WECC Bylaws.
The Midwest Reliability Organization (MRO) began operations on January 1, 2005, as the successor to the Mid-continent Area Power Pool (MAPP), which was formed in 1965. MRO is one of six regional entities under North American Electric Reliability Corporation (NERC) authority. NERC and the regional reliability councils were formed following the Northeast Blackout of 1965. MRO's offices are located in St.Paul, Minnesota. MRO members include municipal utilities, cooperatives, investor-owned utilities, a federal power marketing agency, Canadian Crown Corporations, and independent power producers.
Southwest Power Pool (SPP) manages the electric grid and wholesale power market for the central United States. As a regional transmission organization, the nonprofit corporation is mandated by the Federal Energy Regulatory Commission to ensure reliable supplies of power, adequate transmission infrastructure and competitive wholesale electricity prices. Southwest Power Pool and its member companies coordinate the flow of electricity across approximately 60,000 miles of high-voltage transmission lines spanning 14 states. The company is headquartered in Little Rock, Arkansas.
The Midcontinent Independent System Operator, Inc., formerly named Midwest Independent Transmission System Operator, Inc. (MISO) is an Independent System Operator (ISO) and Regional Transmission Organization (RTO) providing open-access transmission service and monitoring the high-voltage transmission system in the Midwest United States and Manitoba, Canada and a southern United States region which includes much of Arkansas, Mississippi, and Louisiana. MISO also operates one of the world's largest real-time energy markets.
PJM Interconnection LLC (PJM) is a regional transmission organization (RTO) in the United States. It is part of the Eastern Interconnection grid operating an electric transmission system serving all or parts of Delaware, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and the District of Columbia.
A National Interest Electric Transmission Corridor (NIETC) corridor is a geographic region designated by the United States Department of Energy where electricity transmission limitations are adversely affecting American citizens. The Energy Policy Act of 2005 granted the Federal Energy Regulatory Commission (FERC) the authority to create these regions to increase transmission capacity within a short timeframe. If state and local governments fail to issue permits to increase transmission capacity in these areas, FERC can issue federal permits empowering project directors to use eminent domain to purchase property needed to complete projects.
The electrical power grid that powers Northern America is not a single grid, but is instead divided into multiple wide area synchronous grids. The Eastern Interconnection and the Western Interconnection are the largest. Three other regions include the Texas Interconnection, the Quebec Interconnection, and the Alaska Interconnection. Each region delivers power at a nominal 60 Hz frequency. The regions are not usually directly connected or synchronized to each other, but there exist some HVDC interconnectors. The Eastern and Western grids are connected with 1.32 GW.
Power system operations is a term used in electricity generation to describe the process of decision-making on the timescale from one day to minutes prior to the power delivery. The term power system control describes actions taken in response to unplanned disturbances in order to provide reliable electric supply of acceptable quality. The corresponding engineering branch is called Power System Operations and Control. Electricity is hard to store, so at any moment the supply (generation) shall be balanced with demand. In an electrical grid the task of real-time balancing is performed by a regional-based control center, run by an electric utility in the traditional electricity market. In the restructured North American power transmission grid, these centers belong to balancing authorities numbered 74 in 2016, the entities responsible for operations are also called independent system operators, transmission system operators. The other form of balancing resources of multiple power plants is a power pool. The balancing authorities are overseen by reliability coordinators.
A balancing authority (BA) is an entity in the US electric system that is responsible for grid balancing: resource planning and unit commitment ahead of time, maintenance of the load-interchange-generation balance within a balancing authority area and support for real-time load-frequency control. The balancing authorities are connected by metered high-voltage tie lines and grouped into interconnections:
A regional entity (RE) in the North American power transmission grid is a regional organization representing all segments of the electric industry: electric utilities, federal agencies, independent power producers, power market operators, and end-users of the energy. North American Electric Reliability Corporation (NERC) delegates to REs authority to enforce reliability standards, collectively REs, together with NERC, are known as an "ERO Enterprise".
